In Sohag Province, Upper Egypt, decision-makers have proposed constructing new urban communities to overcome population growth and industrial expansions. The investigated site and its surroundings are very close to the Western Cairo–Aswan desert road facing Sohag City. The study site was classified as a high priority for the national social housing project in Sohag’s desert lands. This study aims to identify subsurface karstic features, outline the distribution of weak zones, and estimate the elastic properties of subsurface soil by integrated application of electrical resistivity tomography (ERT) and multichannel surface wave analysis (MASW) with some seismic refraction datasets. Thirty-seven parallel profiles of ERT/MASW were measured with an interprofile spacing of 5 m. Three selected seismic refraction profiles were conducted to estimate the P-wave velocity, together with the S-wave velocity, for calculations of subsurface elastic moduli. Integrating the results of the utilized geophysical methods and calibrating them with the available geologic information optimizes the interpretation process, making the results more accurate and reliable. The findings reveal two shallow subsurface units. The upper unit is highly fractured, weathered limestone and dolomitic limestone, which compose the surface layer of the lower Eocene plateau. This unit shows low S-wave velocity and extremely high electrical resistivity values, extending about 5 m in depth, indicating a less compacted rock unit with limited extent voids. The lower unit consists of fossiliferous and chalky limestone deposits. This unit exhibits moderate to high resistivity values and high S-wave velocity values with thickness values exceeding 20 m. This lower unit is correlated to a compacted and stiff bedrock. The existence of large-scale caves and karstic features characterizes the lower unit. The calculated elastic moduli and the allowable bearing capacity values reveal that the lower unit is more competent than the upper unit; therefore, it is proper for engineering activities and can be a foundation bedrock. Our integrated results generally update the potential use of multimethod geophysical approaches to locate and interpret geotechnical hazards and subsoil conditions at similar karst sites worldwide.